Disposable cutaneous transjector

ABSTRACT

A disposable cutaneous transjecting device is formed of a cylindrically shaped housing having an open end closed by a cover securely attached to the housing. The housing forms a chamber divided by a piston plunger into a subchamber for a liquid medication and another subchamber containing means, such as a compressed gas or a spring member, for displacing the piston plunger and forcing the medication through capillary openings in the cover. Prior to use the means are restrained from displacing the piston plunger. A removable cap forms a seal for the cover. On the exterior of the housing a trigger or similar member is located for releasing the means so that the piston plunger is displaced toward the cover and the medication is ejected through the openings in the cover.

United States Patent [191 Laurens 1 1 DISPOSABLE CUTANEOUS TRANSJECTOR Jan. 29, 1974 Primary ExaminerRichard A. Gaudet Assistant Examiner-G. F. Dunne Attorney, Agent, or FirmToren and McGeady [5 7 ABSTRACT A disposable cutaneous transjecting device is formed of a cylindrically shaped housing having an open end closed by a cover securely attached to the housing. The housing forms a chamber divided by a piston plunger into a subchamber for a liquid medication and another subchamber containing means, such as a compressed gas or a spring member, for displacing the piston plunger and forcing the medication through capillary openings in the cover. Prior to use the means are restrained from displacing the piston plunger. A removable cap forms a seal for the cover. On the exterior of the housing a trigger or similar member is located for releasing the means so that the piston plunger is displaced toward the cover and the medication is ejected through the openings in the cover.

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1 DISPOSABLE CUTANEOUS TRANSJECTOR SUMMARY OF THE INVENTION The present invention is directed to a disposable cutaneous transjecting device and, more particularly, it concerns a relatively small-sized device with a trigger mechanism on its exterior surface for releasing the means which eject the medication from the device under high pressure and velocity.

For some time various devices have been available for the transcutaneous administration of liquid medicaments which replace the usual subcutaneous injection by hypodermic syringe and needle. In such devices liquid medications are administered by forcing fine streams of the liquid, under high pressure, through the dermal tissues. Presently, two different types of devices are available, one the gun type and the other the manual Dermojet type.

The gun type is a heavy-duty, cumbersome apparatus which is approximately the size of an electric hand drill. It is not portable and is connected through tubing to a compressed-gas cylinder. Basically, the gun type is useful in mass-inoculations, such as in the Armed Services and for field-vaccinations in epidemics. Its main disadvantages are its size, weight, and lack of mobility. Further, there have been indications that painful skin lacerations have occurred during its use which may have resulted from faulty handling or from excessive pressure used in operating the device.

The manual Dermojet type of device is about the size and shape of a large foutain pen or pocket flashlight and is a rather expensive instrument. In this type of device the power source is either a small compressed gas cylinder or a powerful spring mechanism. The Dermojet type is disadvantageous in that it involves rather tedious modes of application and reuse. The exact amount of the injectable medication has to be tanked prior to each usage and the springmechanism has to be cocked before each time the medication is administered. Additionally, sterilization procedures have to be regularly performed to assure aseptic operation of the device.

The main advantages achieved by needleless injections are the relative painlessness of the administration of the medication and the absence of trauma previously created by the penetration of the skin tissues with the needle. Accordingly, any source of infection or bleeding resulting from the insertion of the needle is avoided. Further, from a psychological point of view needleless injections are of considerable benefit to patients who are excessively apprehensive of injections.

Therefore, the primary object of the present invention is to provide a small lightweight device for the transcutaneous introduction of liquid medicaments which can be easily manipulated with one hand or only three fingers. Preferably, the device can be inexpensively produced for disposable usage.

Another object of the invention is to provide a completely sterilized device which meets all the requirements for the administration of medications under the strictest rules of asepsis.

Yet another object of the invention is to provide a choice of power sources for the device, that is either the use of compressed gas or of a spring mechanism.

Still another object of the invention is to provide an arrangement containing a premeasured dosage of a medication ready for administration with the medication being readily identifiable by the use of labels applied to the exterior of the device. The time saved in the administration of a premeasured amount of medication could be of life-saving importance in certain emergencies.

Therefore, in accordance with the present invention, a cutaneous transjecting device is provided which includes an elongated housing, preferably cylindrical in shape, and open at one end for the introduction of the power source and the liquid medication. The open end of the housing is closed by a cover member which can be secured in place in various ways. Small diameter capillary passageways are provided through the cover member so that the liquid medication can be forced out under very high pressure. The housing and its cover member form a chamber which is divided by a piston plunger into a pair of subchambers or spaces, one containing the liquid medication and the other containing the power source. The power source, either compressed gas or a spring mechanism, is retained in the chamber for release by a trigger-like mechanism. When the device is to be used, the trigger-like mechanism is actuated and the power source displaces the piston plunger toward the cover member with the liquid medication being forced out through the openings in the cover at such high pressure and velocity that it is capable of passing through the dermal tissues for subcutaneous administration. It should be noted that the present device affords a replacement for subcutaneous injections, however, it cannot be used to replace intramuscular or intravenous injections.

As a disposable device containing a premeasured amount of liquid medication, a removable seal member or cap is provided over the cover member through which the capillary openings pass so that sterile conditions are maintained and there is no possibility of leakage from the chamber.

When compressed gas is used as the power source it is contained within one end of the chamber and the trigger-like mechanism is formed of an elongated rodlike member which is displaceable through the chamber transversely of its elongated direction. The rod-like member has an opening formed through it which can be aligned with an opening into the space containing the compressed gas for releasing the gas when the transjection of the medication is to be effected. If a spring mechanism is used as the power source, it is held in a compressed or cocked position by a clip device and by pressing the clip device on the exterior of the housing the spring is released and drives the piston plunger against the liquid medication forcing it through the openings in the cover member.

By means of the present invention it is possible to provide exactly premeasured dosages of a medication in a sterile condition ready for use merely by removing the seal or cap from the cover on the housing. With the medication being premeasured and the sterile conditions maintained, the problems of human error experienced in the use of conventional hypodermic syringes are overcome to a considerable degree.

There are many potential usages for the device embodying the present invention, for example, it is particularly useful in private practice, hospitals and dentistry, especially for pediatric usage, in emergency kits of various kinds (field medicine), in the personal administration of insulin by diabetics, in the administration of presurgical local anesthesia, and in the intralesional administration of cortico-steroids in dermatology.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a perspective view, approximately to scale, of a transjecting device embodying the present invention;

FIG. 2 is a partial perspective view of the device shown in FIG. 1, illustrating the end through which the liquid medication is administered;

FIG. 3 is an enlarged longitudinal sectional view of the device in FIG. 1 with the power source in the retained position;

FIG. 4 is a view of the member employed in FIG. 3 for retaining the power source;

FIG. 5 is a view. similar to FIG. 3 with the device in position for transjecting the liquid medication and with the member of FIG. 4 displaced for releasing the power source;

FIG. 6 is a partial sectional view taken at right angles to the section shown in FIG. 3; and

FIG. 7 is a sectional view, similar to FIG. 3, showing another form of power source in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION- In the drawing a cutaneous transjector l is shown which is formed of an elongated housing 3 closed at one end and open at its opposite end, preferably the housing is cylindrical in shape with smoothly rounded edges. At its open end the housing 3 is closed by a cover member 5 which, as shown in FIG. 3, is secured by means of a threaded engagement with the housing. The combination of the housing 3 and cover member 5 form an elongated chamber 7 within the transjector l. A plurality of openings 9 extend through the cover member 5 communicating between the chamber 7 and the exterior of the device.

As shown in FIG. 2, a tensor ring 1 1 is formed on and extends about the radially outer end face surface of the cover member encircling the portion containing the openings 9. The tensor ring 11 has a corrugated or roughened surface which aids in keeping the injection site taut and in preventing slippage during administration of the medication.

In the embodiment of the invention shown in FIGS. 3 and 5, a transverse partition wall 13 extends across the chamber 7 intermediate its ends and divides the chamber into subchambers or spaces 7a, 7b, with the space 7a adjacent the cover member arranged to contain the liquid medication and the other space 7b arranged to contain the power source, in the form of a compressed gas, for ejecting the liquid medication.

' Within the space 7a a piston plunger 15 is provided which is displaceable through the space by the power source for forcing the liquid medication through the openings 9 in the cover member 5. As shown in FIGS.

the transversely displaceable member through the chamber and its opening 17a registers with 3 and 5, the inner and outer surfaces of the cover member 5 which register with the space 7a, have a curved configuration, that is the outer surface of the cover member has a convex shape while the inner surface has a concave shape. Similarly, the end surface of the piston plunger closer to the cover member has a convex shape which is provided to approximate the meniscus of the liquid medication to be ejected from the transjector.

The partition wall 13 between the spaces and 7b has an opening through which the compressed gas is released against the piston plunger when the liquid medication is administered. To retain the compressed gas within the space 7b a trigger-like member 17 extends across the end of the space 7a remote from the cover plate and in contact with the surface of the partition wall 13. The trigger-like member is transversely displaceable across the chamber 7 and is provided with an opening or bore 17a which can be moved into registration with the opening 13a in the partition wall for releasing the compressed gas against the piston plunger 15.

Alternatively, to increase the frictional engagement of the trigger-like member 17 it can be arranged to pass through the partition wall instead of in contact with only one of its faces.

In FIG. 3, the transversely displaceable member 17 is shown with its opening 17a laterally displaced from the opening 13a in the partition wall 13 so that the compressed gas is retained within the space 7b. In this position a triggering element or release button 17b formed on the outer end of the member is spaced outwardly from the housing 3. At its opposite end, the trigger-like member 17 has a nail-head safety element which prevents it from being displaced laterally out of the housing in the direction of the release button 17b. Initially, a piece of tape 19, for instance a medication and dosage label, or similar means is provided over the nailhead safety element 170 so that the trigger-like member cannot be accidentally displaced and release the power source. On the trigger-like member 17, spaced from the release button 17b so that it is located within the walls of the housing 3, is a annular shaped part 17d which provides frictional engagement with the housing to assure that a positive displacing action or force is exerted against the release button 17b before 17 moves the opening 13a in the partition wall 13.

In FIG. 1 a removable seal or protective cap 21 is provided over the end of the device containing the openings 9. Preferably, the protective cap is formed of soft polyethylene material which is easily removable for uncovering the end face of the cover member which is applied to the transjection site when the device is to be used. Further, other seal members presently available could be used in place of the soft polyethylene cap.

In FIG. 6 the trigger-like member 17 is shown in a plane normal to that in FIG. 3 with its upper surface in engagement with the lower surface of the partition wall 13 so that a positive seal is provided about the opening 13a to assure that compressed gas does not leak from the space 7b into contact with the surface of the piston plunger 15.

In FIG. 7 another embodiment of the invention is shown with a spring member 2 being used as the power source in place of the compressed gas. Similar parts in the embodiments shown in FIGS. 3 and 7 have the same reference numerals. Intermediate the ends of the chamber 7 support elements 23 extend radially inwardly and provide displaceable abutments against which the spring member 2 seats when it is held in its retained position. A clip-type trigger member 25 is accessible on the exterior of the housing 3 and when the triggering member is pushed inwardly on the opposite sides of the housing the support elements 23 are displaced outwardly releasing the spring member 2 so that it forces the piston plunger toward the cover member 5 and ejects the liquid medication filled into the chamber through the openings 9. Safety means can be incorporated into the triggering member 25 so that it cannot be accidentally actuated for releasing the spring mechanism.

Principally the transjecting device is intended for disposable use and for such use would be constructed of a tough, firm plastic, such as Nylon, Vinyl and the like, which have sufficient strength to contain the power sources without distortion and to avoid any fracture or bending when the power source is released and the liquid medication discharged from the chamber. Furthermore, the material used should be chemically inert to avoid any alteration in the chemical structure of the liquid medication contained in the device. In addition, the material used must be capable of maintaining its effectiveness during sterilization. A silicon treated medication chamber could ease the propulsion step considerably.

As mentioned above, the transjecting device in accordance with the present invention is primarily intended for disposable use and can be operated with one hand or by only using three fingers. An example of the size of the device is as follows: the housing is cylindrical being 4 to 5cm in length and 1.5 to 2 cm in diameter. The application or proximal end, the end which contacts the skin in administering the medication, is slightly convex and contains four to eight openings each having a diameter of approximately 1 to 2 mm in order to facilitate the passage of micro-crystalline and precipitate solutions. The opposite end of the housing is flat. At the proximal end and surrounding the convexly shaped portion is the tensor ring having a width in the radial direction of approximately 2 to 3mm and having a roughened or corrugated configuration which aids in keeping the transjection side taut and in preventing any slippage during administration of the medication. In the embodiment shown in FIG. 3, with the trigger-like member 17 in position for retaining the power source the release button 17b is spaced outwardly from the housing a distance equal to the offset of the opening 17a in the member 17 from the opening 13a in the partition wall 13. The walls of the housing 3 and the cover member 5 are between 2 and 4 mm in thickness leaving sufficient room within the chamber formed by the housing and cover member for the power source and the liquid medication.

The triggering mechanisms used for the different power sources must have sufficient resistance to applied pressure to avoid any premature or accidental discharge of the medication. A built-in friction factor in the material forming the mechanism would provide an additional safety measure.

To facilitate the assembly of the transjecting device 1 its chamber 7 is formed by the housing 3 and the separate cover member 5. Initially, the power source is supplied into the chamber and held in the retained position, then, after the insertion of the piston plunger 15, a premeasuredamount of the liquid medication is charged into the chamber and the cover member 5 is secured to the housing so that a liquid tight seal is provided. As an alternative, the length of the cover member 5 could be increased so that the premeasured dosage of medication is filled into the cover member and is closed by inserting the piston plunger 15 into the cover member, then the cover member could be attached to the housing 3. Various types of seals can be used, for instance, as shown in FIGS. 3 and 5 a threaded closure can be used, further the cover member and housing can be thermally fused together, note FIG. 7, or a bayonet type closure can be employed. Due to the capillary nature of the openings 9 through the cover member 5 there should be no leakage through the openings. In addition, to maintain sterile conditions at the proximal end of the device which is applied to the skin area during the administration of the medication, a removal seal member, such as a soft polyethylene type cap, is fitted over the end of the transjecting device during storage, note FIG. 1.

In another embodiment the premeasured dosages of medication could be supplied in containers formed by the cover member 5 and the piston plunger 15 and then attached to a member such as the housing 3 containing the power source prior to use.

When the device such as shown in FIG. 1 is ready for use, the seal 1 is removed from the cover member and the tape 19 or other safety means is removed from the end of the trigger-like member 17 which releases the power source. In FIG. 3 the seal 21 has been removed, however, the tape 19 which restrains the trigger-like member 17 from transverse displacement is still in position. In FIG. 5 the tape is shown at least partly removed from the housing with the trigger-like member 17 pushed laterally through the housing so that its hole 17a aligns with the opening 13a through the partition wall 13 and the compressed gas power source expands from the space 7b and exerts considerable pressure against the piston plunger 15 driving it toward the cover member 5. As the piston plunger is displaced by the compressed gas, due to the laws of hydraulics, the liquid medication is forced at very high pressures and velocity through the openings 9 in the cover member and will pass in very fine streams through the cutaneous tissues providing the transjection of the liquid medication without the use of any needle and in a manner which is almost completely painless and without trauma.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

l. A disposable cutaneous transjecting device comprising a self-contained manually operable transjector, said transjector comprising an elongated housing open at one end and closed at the other end and forming a chamber within said housing, a cover member secured to the open end of said housing and providing a closure for said chamber therein, said cover member having at least one small diameter capillary passageway therethrough in its surface extending across the open end of said housing and said passageway communicating between said chamber and the exterior surface of said cover member, a piston plunger fitted within said chamber for displacement therein in the axial direction of said housing extending between its ends and said pis ton plunger dividing said chamber into a pair of spaces with the one of said spaces adjacent said cover member arranged to contain a liquid medicament therein,

means within the other one of said spaces for displacing said piston plunger toward said cover member, manually actuatable means accessible on the exterior of said housing for retaining said means from displacing said piston plunger and for releasing said means for displacing said piston plunger through the one of said spaces toward said cover member so that the liquid medicament contained in said one of said spaces is displaced therefrom through said passageway in said cover member, a removable seal member fitted over the exterior surface of said cover member containing said passageway for preventing contamination, said means within the other one of said spaces for displacing said piston plunger comprises a quantity of compressed gas, said actuatable means comprises a partition wall extending transversely of the elongated direction of said housing and located on the opposite side of said piston plunger from said cover member, said partition wall having an opening therethrough for admitting the compressed gas into contact with said piston plunger, and a transversely displaceable member arranged to seal the opening in said partition wall and having an opening therethrough which is registerable with the opening in said partition wall for releasing said compressed gas into contact with said piston plunger for discharging the medicament from said device, whereby said device is usable as a disposable element containing a required dosage of a medicament ready for transjection upon the removal of said seal member.

2. A cutaneous transjecting device, as set forth in claim 1, characterized in that said transversely displaceable member comprising an elongated rod-like member extending through said housing from one side to the. other with the opening being provided therethrough, a release element provided on one end of said rod-like member so that when said rod-like member is positioned to retain said means from displacing said plunger said release element is positioned outwardly from the outer surface of said housing and when said rod-like member is moved through said housing said release element is displaced toward said housing and acts as a stop preventing said rod-like member from further passage through said housing and the opening through said rod-like member is aligned with the opening in said partition wall and admits the compressed gas to said piston plunger for ejecting the medication from the one of said spaces adjacent said cover member.

3. A cutaneous transjecting device, as set forth in claim 2, characterized in that said rod-like member having an annular protuberance formed thereon and acting as a safety element for preventing accidental displacement of said rod-like member through said housing, said protuberance being in contact with the walls forming said housing when said rod-like member is in position for retaining said compressed gas from displacing said piston plunger.

4. A cutaneous transjecting device, as set forth in claim 2, characterized in that removable means are attached to the exterior of said housing on the opposite end of said rod-like member from said release element and are arranged to prevent said rod-like member from being movably displaced through said housing.

5. A cutaneous transjecting device, as set forth in claim 1, characterized in that the exterior surface of said cover in alignment with said chamber is convex.

6. A cutaneous transjecting device, as set forth in claim 5, characterized in that the inner surface and the outer surface of said cover member are in substantially parallel relationship and the surface of said piston plunger closer to said cover member having a convex configuration approximating the meniscus of the liquid medication to be contained within the one of said spaces forming said chamber.

7. A cutaneous transjecting device, as set forth in claim 1, characterized in that said cover member having screw threads formed thereon and said housing having similar screw threads thereon adjacent its open end for effecting threaded engagement between said cover and said housing.

8. A cutaneous transjecting device, as set forth in claim 1, characterized in that said cover member being arranged to fit over the end of said housing and is thermally fused to said housing.

9. A cutaneous transjecting device, as set forth in claim 5, characterized in that the radially outer suface of the end exterior face of said cover member encircling the convexly shaped surface of said cover member containing and passageways having alternating ridges and valleys forming a roughened surface for avoiding slippage of said device when applied to the transjecting side and for maintaining the transjecting side taut.

10. A cutaneous transjecting device, as set forth in claim 9, characterized in that said alternating ridges and valleys extending radially on the end face of said cover member have a width in the radial direction of approximately 2 to 3 mm.

11. A cutaneous transjecting device, as set forth in claim 1, characterized in that said removable seal member is formed of a soft polyethylene material.

12. A cutaneous transjecting device, as set forth in claim 1, wherein said housing is cylindrically shaped and is formed of a lightweight plastic material, said housing being approximately 4 to 5 cm in length and 1.5 to 2 cm in diameter and the walls of said housing being in the range of 2 to 4 mm in thickness, and the openings in said cover member being approximately 1 to 2 mm in diameter. 

1. A disposable cutaneous transjecting device comprising a selfcontained manually operable transjector, said transjector comprising an elongated housing open at one end and closed at the other end and forming a chamber within said housing, a cover member secured to the open end of said housing and providing a closure for said chamber therein, said cover member having at least one small diameter capillary passageway therethrough in its surface extending across the open end of said housing and said passageway communicating between said chamber and the exterior surface of said cover member, a piston plunger fitted within said chamber for displacement therein in the axial direction of said housing extending between its ends and said piston plunger dividing said chamber into a pair of spaces with the one of said spaces adjacent said cover member arranged to contain a liquid medicament therein, means within the other one of said spaces for displacing said piston plunger toward said cover member, manually actuatable means accessible on the exterior of said housing for retaining said means from displacing said piston plunger and for releasing said means for displacing said piston plunger through the one of said spaces toward said cover member so that the liquid medicament contained in said one of said spaces is displaced therefrom through said passageway in said cover member, a removable seal member fitted over the exterior surface of said cover member containing said passageway for preventing contamination, said means within the other one of said spaces for displacing said piston plunger comprises a quantity of compressed gas, said actuatable means comprises a partition wall extending transversely of the elongated direction of said housing and located on the opposite side of said piston plunger from said cover member, said partition wall having an opening therethrough for admitting the compressed gas into contact with said piston plunger, and a transversely displaceable member arranged to seal the opening in said partition wall and having an opening therethrough which is registerable with the opening in said partition wall for releasing said compressed gas into contact with said piston plunger for discharging the medicament from said device, whereby said device is usable as a disposable element containing a required dosage of a medicament ready for transjection upon the removal of said seal member.
 2. A cutaneous transjecting device, as set forth in claim 1, characterized in that said transversely displaceable member comprising an elongated rod-like member extending through said housing from one side to the other with the opening being provided therethrough, a release element provided on one end of said rod-like member so that wHen said rod-like member is positioned to retain said means from displacing said plunger said release element is positioned outwardly from the outer surface of said housing and when said rod-like member is moved through said housing said release element is displaced toward said housing and acts as a stop preventing said rod-like member from further passage through said housing and the opening through said rod-like member is aligned with the opening in said partition wall and admits the compressed gas to said piston plunger for ejecting the medication from the one of said spaces adjacent said cover member.
 3. A cutaneous transjecting device, as set forth in claim 2, characterized in that said rod-like member having an annular protuberance formed thereon and acting as a safety element for preventing accidental displacement of said rod-like member through said housing, said protuberance being in contact with the walls forming said housing when said rod-like member is in position for retaining said compressed gas from displacing said piston plunger.
 4. A cutaneous transjecting device, as set forth in claim 2, characterized in that removable means are attached to the exterior of said housing on the opposite end of said rod-like member from said release element and are arranged to prevent said rod-like member from being movably displaced through said housing.
 5. A cutaneous transjecting device, as set forth in claim 1, characterized in that the exterior surface of said cover in alignment with said chamber is convex.
 6. A cutaneous transjecting device, as set forth in claim 5, characterized in that the inner surface and the outer surface of said cover member are in substantially parallel relationship and the surface of said piston plunger closer to said cover member having a convex configuration approximating the meniscus of the liquid medication to be contained within the one of said spaces forming said chamber.
 7. A cutaneous transjecting device, as set forth in claim 1, characterized in that said cover member having screw threads formed thereon and said housing having similar screw threads thereon adjacent its open end for effecting threaded engagement between said cover and said housing.
 8. A cutaneous transjecting device, as set forth in claim 1, characterized in that said cover member being arranged to fit over the end of said housing and is thermally fused to said housing.
 9. A cutaneous transjecting device, as set forth in claim 5, characterized in that the radially outer suface of the end exterior face of said cover member encircling the convexly shaped surface of said cover member containing and passageways having alternating ridges and valleys forming a roughened surface for avoiding slippage of said device when applied to the transjecting side and for maintaining the transjecting side taut.
 10. A cutaneous transjecting device, as set forth in claim 9, characterized in that said alternating ridges and valleys extending radially on the end face of said cover member have a width in the radial direction of approximately 2 to 3 mm.
 11. A cutaneous transjecting device, as set forth in claim 1, characterized in that said removable seal member is formed of a soft polyethylene material.
 12. A cutaneous transjecting device, as set forth in claim 1, wherein said housing is cylindrically shaped and is formed of a lightweight plastic material, said housing being approximately 4 to 5 cm in length and 1.5 to 2 cm in diameter and the walls of said housing being in the range of 2 to 4 mm in thickness, and the openings in said cover member being approximately 1 to 2 mm in diameter. 